1. Field of the Invention
The present invention relates to a data driver and a light emitting diode display device including the same, and more particularly, to a data driver and a light emitting diode display device that display an image with desired brightness.
2. Discussion of Related Art
Various flat panel displays have recently been developed as alternatives to the relatively heavy and bulky cathode ray tube (CRT) display device. The flat panel displays include liquid crystal display devices (LCD), field emission display devices (FED), plasma display panels (PDP), light emitting diode display devices (OLED), and the like.
Among the flat panel display devices, the light emitting diode display device can emit light by electron-hole recombination. The light emitting diode display device has the advantages of relatively fast response time and relatively low power consumption. Generally, the light emitting diode display device uses a transistor in each pixel for supplying current corresponding to a data signal to a light emitting device, causing the light emitting device to emit light.
FIG. 1 illustrates a conventional light emitting diode display device 100 that includes a display region 30 including pixels 40 formed in a region defined by the intersection of scan lines S1 through Sn and data lines D1 through Dm. The conventional display 100 also includes a scan driver 10 to drive the scan lines S1 through Sn, a data driving part 20 to drive the data lines D1 through Dm, and a timing controller 50 to control the scan driver 10 and the data driving part 20.
The timing controller 50 generates a data control signal DCS and a scan control signal SCS corresponding to an external synchronization signal. The data control signal DCS and the scan control signal SCS are supplied from the timing controller 50 to the data driving part 20 and the scan driver 10, respectively. Further, the timing controller 50 supplies external data to the data driving part 20.
The scan driver 10 receives the scan control signal SCS from the timing controller 50. The scan driver 10 generates scan signals on the basis of the scan control signal SCS and supplies the scan signals to the scan lines S1 through Sn.
The data driving part 20 receives the data control signal DCS from the timing controller 50. The data driving part 20 generates data signals on the basis of the data control signal DCS and supplies the data signals to the data lines D1 through Dm while synchronizing with the scan signals.
The display region 30 receives first voltage ELVDD and second voltage ELVSS from an external power source, and supplies them to the pixels 40. When the first voltage ELVDD and the second voltage ELVSS are applied to the pixels 40, each pixel 40 controls and causes a current corresponding to the data signal to flow from a first power line supplying the first voltage ELVDD to a second power line supplying the second voltage ELVSS via a light emitting device, thereby emitting light corresponding to the data signal.
Thus, in the conventional light emitting diode display device 100, each pixel 40 emits light with a predetermined brightness corresponding to the data signal received. The pixels 40, however, cannot emit light with a desired brightness because the transistors used in the pixels 40 have different threshold voltages. Further, in the conventional light emitting diode display device 100, there is no method of measuring and controlling the real current in each pixel 40.